Structural Determinants of 4-Chloro-<i>m</i>-cresol Required for Activation of Ryanodine Receptor Type 1
作者:Alan R. Jacobson、Scott T. Moe、P. D. Allen、James D. Fessenden
DOI:10.1124/mol.106.022491
日期:2006.7
4-Chloro- m -cresol (4-C m C) is a clinically relevant activator of the intracellular Ca2+ release channel, the ryanodine receptor isoform 1 (RyR1). In this study, the chemical moieties on the 4-C m C molecule required for its activation of RyR1 were determined using structure-activity relationship analysis with a set of commercially available 4-C m C analogs. Separate compounds each lacking one of the three functional groups of 4-C m C (1-hydroxyl, 3-methyl, or 4-chloro) were poor activators of RyR1. Substitution of different chemical groups for the 1-hydroxyl of 4-C m C resulted in compounds that were poor activators of RyR1, suggesting that the hydroxyl group is preferred at this position. Substitution of hydrophobic groups at the 3-position enhanced bioactivity of the compound relative to 4-C m C, whereas substitution with hydrophilic groups abolished bioactivity. Likewise, 4-C m C analogs with hydrophobic groups substituted into the 4-position enhanced bioactivity, whereas hydrophilic or charged groups diminished bioactivity. 4-C m C analogs containing a single hydrophobic group at either the 3- or 4-position as well as 3,5-disubstituted or 3,4,5-trisubstituted phenols were also effective activators of RyR1. These results indicate that the 1-hydroxyl group of 4-C m C is required for activation of RyR1 and that hydrophobic groups at the 3,4- and 5-positions are preferred. These findings suggest that the 4-C m C binding site on RyR1 most likely consists of a hydrophilic region to interact with the 1-hydroxyl as well as a hydrophobic region(s) to interact with chemical groups at the 3- and/or 4-positions of 4-C m C.
4-Chloro- m -cresol (4-C m C) 是细胞内 Ca2+ 释放通道(兰尼碱受体亚型 1 (RyR1))的临床相关激活剂。在这项研究中,使用一组市售的 4-C m C 类似物进行结构-活性关系分析,确定了 4-C m C 分子上激活 RyR1 所需的化学部分。各自缺乏 4-C m C 三个官能团(1-羟基、3-甲基或 4-氯)之一的单独化合物是 RyR1 的不良激活剂。用不同的化学基团取代 4-C m C 的 1-羟基产生的化合物是 RyR1 的不良激活剂,表明在该位置优选羟基。相对于4-C m C,3位疏水基团的取代增强了化合物的生物活性,而亲水基团的取代消除了生物活性。同样,4-位疏水基团取代的4-C m C类似物增强了生物活性,而亲水或带电基团降低了生物活性。在3-位或4-位含有单个疏水基团的4-C m C类似物以及3,5-二取代或3,4,5-三取代酚也是RyR1的有效激活剂。这些结果表明,4-C m C 的 1-羟基是 RyR1 活化所必需的,并且优选 3,4-和 5-位的疏水基团。这些发现表明,RyR1 上的 4-C m C 结合位点很可能由与 1-羟基相互作用的亲水区域以及与 3-和/或 4-羟基相互作用的疏水区域组成。 -4-C m C的位置。